(1) Field of the Invention
The present invention relates to a technique to distribute, receive, record, and play back digital works over a network.
(2) Description of the Related Art
Thanks to recent technological advances, digital works, such as digitized documents, music, images, and programs, have been distributed over a network typified by the Internet, which allows users to easily retrieve various digital works via a network, and record the retrieved digital works onto a separate recording medium to play back.
However, the above advantage that users are allowed to conveniently replicate digital works is inevitably attended with a problem in that the copyrights of digital works may be infringed easily.